1. Field of the Invention
This invention relates to a seismic response control method, in which a seismic response control device comprised of a variable damping device or an actuator is installed in a structure, and seismic response control of the structure is performed by controlling a characteristic of restitutive force, that is, hysteresis in a structural body installed with the seismic response control device.
2. Description of the Prior Art
In a prior art, a passive seismic response control device covers a dynamic vibration absorber which reduces vibration of a structure in response to reaction force of a weight mounted on the top or inside of the structure by synchronizing the weight supported by a spring and a damper with a natural period of the structure (See Japanese Patent Publications B2-H3-38386 and B2-H5-55741, for instance).
Further, a passive seismic response control device adopting a damping device covers a device which attains a reduction in vibration of a building by setting a damping coefficient of a damping device, which is disposed in a frame composed of columns and beams of a structure so as to be connected to an earthquake-resisting component, at a certain value or automatically varying the damping coefficient according to the state of vibration (See Japanese Patent Publications B2-2513356 and B2-2528589, for instance).
On the other hand, the present inventors have developed a variety of active seismic response control systems such as a seismic response control method, in which an earthquake-resisting component is installed in a frame composed of columns and beams of a structure through a variable stiffness device or a variable damping device, and the evaluation of damping capacity of the structure is made by varying a stiffness of the frame composed of columns and beams with the variable stiffness device, or varying a damping coefficient of the variable damping device, and a seismic response control method, in which damping force generated from a variable damping device is applied as control force (See Japanese Patent Publications B2-H7-42811 and B2-H7-45781, for instance).
In a passive seismic response control method, a damping device 11 is installed in each story of a building as shown in FIG. 18, for instance, and as a result, this method particularly offers the advantages of dispensing with the installation of a sensor and the supply of external energy, whereas it has the disadvantages of needing to set a damping coefficient relatively to a specific vibration mode or being highly restricted in vibration damping effects by a stiffness of a mounting brace or the like installed with the damping device.
On the other hand, according to an active seismic response control method adopting a variable damping device, a sensor 22 is disposed on portions of a building as shown in FIG. 19, for instance, a seismic or like response of the building is synthetically judged by a computer 23, and a command is issued to a variable damping device 21 disposed in each story of the building to provide high damping capacity to the building.
However, even in this case, it is necessary to perform complicated analysis by the computer on the basis of information from the sensor in each story. Further, detailed advance examinations are required for adjustment.
An object of the present invention is to solve the above problems, and, in a seismic response control method for a structure adopting a seismic response control device such as a variable damping device and an actuator, to enable efficient seismic response control by controlling force generated from the device so as to maintain a hysteresis characteristic on a story basis, or vary the hysteresis characteristic under specific conditions.